This invention relates generally to blood lancets, and more particularly to a lancet for finger piercing with improved structural safety features and functional benefits.
The letting of small quantities of blood for certain testing purposes has become part of an extremely important diagnostic technique. However, with increasing utilization of this technique, not only in institutional settings, but also most recently in home use wherein diabetics and certain other patients periodically let and test their own blood samples, improved devices have been developed and marketed to facilitate this procedure.
As a substitute for early techniques of simply manually pricking the finger with a pointed needle, various systems have been invented and marketed which facilitate this function. These systems typically include a reusable carrier mechanism and a disposable lancet which is installed and used in conjunction therewith.
Two lancets for use in conjunction with these carrying devices are known to applicant under the trademarks MONOLET by Sherwood Medical Industries, the other under the trademark MICROFINE by Beckton Dickinson and Company.
One such lancet carrier device is disclosed in U.S. Pat. No. 4,230,118 which is directed to a device marketed by Owen Mumford, Ltd. under the trademark AUTOLET which forces a spring-loaded pivoted arm carrying a replaceable disposable lancet through a replaceable apertured plate which is pressed against the patient's finger. Controlled penetration and pressure are achieved to effect a quick and relatively painless puncturing of the skin of the finger. Another such unpatented device is now marketed under the trademark AUTOLANCE by Becton Dickinson and Company. This device, used in conjunction with the disposable MICRO-FINE lancet, is similar in function to the '118 patent except that the device is longitudinal in nature and does not include a replaceable pad for pressing against the skin. Sherwood also produces a carrier under the trademark MONOJECTOR which is similar to the AUTOLANCE device.
All of the above prior art devices, however require that a lancet surrounded in molded plastic be installed into and removed from the carrier each time so as to reduce the possibility of transmitting blood diseases from one patient to another. However, because of the nature of replacing lancets, the exposed piercing tip may accidentally puncture the operator's finger during the replacement procedure. Further, these lancets are installed and removed with the carrier in its cocked position. This risk is particularly acute to the medical practitioner who inadvertently pierces his own finger after use, thus encountering the risk of contamination of his own blood supply if the patient carries contaminated blood. There appears to be an additional risk associated with the AUTOLANCE device in that the portion of the reusable mechanism which presses against the patient's finger and comes in contact with blood let is not replaceable and must somehow be sterilized after each use.
The present invention avoids all of the above limitations while providing an economical, disposable and, if desired, simple lancet which is useable only one time. The invention eliminates or substantially reduces risk of inadvertent piercing of a medical technician's fingers because the piercing tip is always concealed except during momentary use. Further, the entire device is disposable rather than being replaceable within a larger reusable mechanism during which time needle exposure would otherwise serve as a danger to the technician.